1. Technical Field
The present invention relates to a delay control circuit and a method of controlling a delay of a semiconductor device, and more particularly, to a circuit and a method, which detect and control a delay time in accordance with a change in operating conditions of the semiconductor device.
2. Discussion of the Related Art
A delay time of a delay circuit in a semiconductor device typically changes according to operating conditions affecting the semiconductor device. In particular, operating conditions such as a fabrication process, temperature, and voltage may change of the delay time and thus affect the operation of the semiconductor device.
For example, when the delay time is changed, a design margin may be reduced and the semiconductor device or circuit on which it is embedded may operate abnormally. In other words, a deviation in the delay time due to a fabrication process, temperature or voltage may exert a significant influence on the reliability and stability of the semiconductor device.
For example, if the temperature of the semiconductor device exceeds a certain operating threshold, the delay time may increase and erroneous data may be output therefrom. Similarly, if a supply voltage of the semiconductor device changes, the delay time may vary thus causing unwanted data to be output.
As such a need exists for a delay circuit for use with a semiconductor device that is capable of maintaining a stable delay time in view of operating conditions that may adversely affect the reliability of the semiconductor device.